The “Synthacon” monophonic analog synthesizer, manufactured by Salt Lake City based company “Steiner Parker” was released in 1975, directly competing with Moog’s and ARP’s flagship synths of the time, “Minimoog” and “Odyssey”. The 3 VCO synth prominently features a switchable multimode “Sallen Key”-filter, with Low-, Band- and High-pass capabilities, which could be driven into self-oscillation.

Unlike its competition, the Synthacon’s filter uses positive feedback, preventing its audio output from losing amplitude when increasing the resonance. The Synthacon holds a broad variety of (cross-)modulation and routing possibilities, such as FM, Sample & Hold and a Trigger Generator, which are controlled using the many switches, largely expanding the sonic spectrum of the synth. The Synthacon is considered relatively rare, especially in Europe, as only a few hundred units were ever made and sold.